Bulk materials are normally loaded onto railway freight cars or wagons, by passing a number of mutually hitched wagons through a loading zone above which there is arranged a storage unit or silo in which bulk materials, such as ore concentrates or pellets, are stored. The material is discharged from the silo down into an underlying wagon through the medium of a chute provided with an outlet opening, referred to here as a material delivery chute. Loading of the wagons takes place automatically and the outlet end of the delivery chute is provided with a flap whose width is sufficient to cause the material pouring from the chute to be distributed uniformly in the wagon.
Australian Publication B 55576/86 teaches one such type of loading arrangement where the intention is to distribute the weight of the material equally at both ends of the wagon while, at the same time, maintaining an essentially constant height, or level of the material in the wagon, therewith to utilize the capacity of the wagon effectively. To this end, the wagon is weighed and its height is determined and also its passage through specific points. On the basis of this information, the material delivery chute is controlled to deliver a specific volume or weight of material to the wagon and to distribute the material uniformly in the wagon while levelling the material therein at the same time.
When seen against the background of the number of wagons that annually transport bulk materials of the aforesaid kind, such as ore, ore concentrates or pellets, it is a natural aim to utilize the load capacity of each wagon and each wagon train to a maximum. Wagon wheels and wagon baskets become worn and in time a wagon may become one or two tonnes lighter in weight. Its loading capacity has not diminished, however. The endeavour to constantly utilize the full load capacity of individual wagons or freight cars is readily understandable.